Available fluorophore options include two ATTO 488, two ATTO 565, or two ATTO 647N labels.
This biotinylated double-stranded λ-DNA (48,502 bp) is labeled with two ATTO fluorophores positioned at 33,786 bp and 44,826 bp. Additionally, the DNA is modified with three biotins at each 3’ end to allow tethering in optical tweezers. The fixed distance between the fluorophores can serve as a molecular ruler for precise localization of protein-binding sites along the DNA sequence. Typically, ≥70% of the tethers display both fluorophores.
For the tethering procedure, refer to the protocol for biotinylated λ-DNA. To preserve fluorophore stability during imaging, a buffer containing oxygen scavengers is recommended.
Estimated for 20 experimental sessions on the C-Trap.
Estimated 1-4 weeks delivery time.